Simultaneous formation of P–C/P–O-cage phosphoranes in the reaction of 2-[(2-methylcarbonyl)phenyloxy]-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane with hexafluoroacetone

Reaction of 2-[(2-methylcarbonyl)phenyloxy]-4,4,5,5-tetra-methyl-1,3,2-dioxaphospholane with hexafluoroacetone leads to the simultaneous formation of two P–C/P–O-cage phosphoranes. The P–C-cage species does not convert to the P–O-cage one neither under the kinetically (3 years, 20–25 °C, dichloromethane) nor under the thermo-dynamically controlled conditions (110 °C, toluene, 8 h).